An old high school that has been all but empty for almost three decades will be demolished to make way for a 421,500-square-foot industrial redevelopment along Interstate 25 in Adams County.

Denver-based Westfield Company purchased the old Mapleton High School property at 601 E. 64th Ave. from Mapleton Public Schools in December. The sale price was $7.08 million, according to district officials.

Westfield’s plans for the 23.8-acre site call for four industrial buildings ranging in size from 43,500 square feet to 145,000 square feet. The first one is scheduled to be completed in November.

All of the buildings are being constructed on spec, without any lease commitments in advance. Called Hub 25, the development will be able to accommodate industrial users needing 20,000 square feet up to the full capacity of 421,500.

“Growing up here in Denver, I’ve driven by the property a thousand times. In the last 20 years, it’s just sat there vacant,” Westfield partner Randy Schwartz said Tuesday. “In the development world, you think, ‘Oh, I’ve got to call on that property and sooner and later they’ll come around.’ That’s what happened with this one.”

Located in a largely industrial corridor between I-25 and Washington Street, the old Mapleton High closed its doors in 1988 due to declining enrollment and rising expenses.

In the years since, the campus has temporarily housed various groups, including two different charter schools, a boxing club, practices for a local “big band” and a baseball group, according to the district. The Thornton Police Department also used the building for training and the district for storing things like surplus desks.

Mapleton decided to market the property after determining it was “more valuable to the district to sell than to keep, allowing the district to invest in future needs,” superintendent Charlotte Ciancio said in an e-mail.

“As that southern portion of the district continues to see business and industrial development, other areas of the district are welcoming new families and preparing to break ground on new housing units,” Ciancio said. Mapleton students mostly come from old Thornton and parts of unincorporated Adams County.

For industrial tenants, on the other hand, the site offers a prime location in the Central Denver submarket — with 1,800 linear feet of I-25 frontage and 213,000 cars passing by every day, said Tyler Carner, senior vice president with CBRE Denver Industrial & Logistics Services.

In addition to representing the school district in the sale, Carner and CBRE’s Jeremy Ballenger are handling the leasing for Westfield.

“As Denver has grown, a lot of the new development has been forced to go northeast or southeast into more suburban areas,” Carner said. “It’s extremely rare and extremely unique to have a site for industrial development in central Denver of any size and scale.”

That Hub 25’s design allows the buildings to be divided into smaller footprints for multiple tenants should also help attract businesses, Carner said.

On the small end, the buildings can comfortably be broken down into spaces of 20,000 to 25,000 square feet.

“The average-size industrial user in the Denver market is somewhere in the range of 31,000 square feet,” he said. “The vast majority of space delivered in this entire construction cycle has been for users over 100,000 square feet.”

Denver’s industrial real estate market has experienced 23 consecutive quarters of positive leasing activity, even as the cost of renting, squeezed by high demand and low supply, surpasses highs set before the recession, according to CBRE data.

The average industrial asking lease rate jumped to $7.23 per square foot triple net in the fourth quarter of 2015, up 4.2 percent year over year and 2.6 percent from the third quarter.

Just to the south of the old Mapleton site, another new 124,000-square-foot industrial warehouse is already under construction.

Corum Real Estate Group’s Central 62 project, located on a former alfalfa farm at I-25 and East 62nd Avenue, is also targeting mid-size industrial tenants.

Construction at Hub 25 could begin within 30 to 45 days, Schwartz said. The final building should be ready in early 2017.

“If you look at the central industrial market today, other than what Trammell Crow is building (at Crossroads Commerce Park) and (Corum’s) project, we haven’t had Class A industrial buildings built in 15 years,” Schwartz said. “There’s a lot of older warehouses that people have had to work around to be in this area.”

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